Electrode feeding mechanism for arc lamps



Nov. 8, 1938. w. K. KRIEG ET AL ELECTRODE FEEDING MECHANISM FOR ARCLAMPS Filed Jan. 22, 1938 2 Sheets-Sheet l Fig. 1

NOV. 8, 1938. w K KRlEG ET AL 2,136,082

ELECTRODE FEEDING MECHANISM FOR ARC LAMPS Filed Jan. 22, 1938 2Sheets-Sheet 2 [/2 van ions.-

Patented Nov. 8, 1938 UNITED STATES ELECTRODE FEEDING MECHANISM FORLAMPS a Walter Kurt Krieg and Ernst Scheller, Jena, Germany, Germanyassignors to the llnn Carl Zelas, Jena,

Application January 22, 1938, Serial No. 186,376

In Germany Claims.

angle.

A mechanism of said kind is, owing to simple construction, very reliableand can be'comparatively small, so that the electrode head interceptsthe light are to a comparatively small extent only. To ensure asreliable an electrode displacement as possible, the interior wheelsurface ac- 4 tuating the electrode is conveniently provided with pinsor teeth of hard material.

In a mechanism according to theinvention, various speeds can be obtainedby providing that the inclination of the axis of rotation of the drivingwheel withrespect to the electrode axis be varied. It is thus possibleto control for instance the feeding speed according to differentelectrode materials. When the inclination of the two axes relative toeach other is variable by means of an electromagnet controlled by thelight-arc voltage or actuated by means of a thermostat, irregularitiesin the electrode material can be dealt with in the feed automatically.

The acompanying drawings illustrate a constructional example of theinvention. Figure 1 shows in part-sectional view the entire mechanism;Figure 2 shows a section through line 2-4 A in Figure 1; Figure 3 is apartial diagram; Figure. 4 shows a section through line 4-4 in Figure 1;

Figure 5'shows a section through line 5-5 m Figure 1; and Figure 6 isthe diagram of a single part.

In thisconstructional example, the electrode, designated a, is in aholder b. The electrode it passes through a central orifice in anannular wheel 0 into which protrude the points of steel screws 0 thesepoints engaging the electrode a.

The wheel 0, which is mounted in a ball bearing 11 and rotatable aboutan axis A-A, has teeth 0 in mesh with a bevel wheel e. The wheel e ismounted in an arm I, which carries the ball bearing d. By means of aflexible shaft e and a pair of bevel wheels e e the wheel e is connectedto the armature of an electromotor g. A rod 7!. extends into the arm 1and is so fixed to same by a screw 11 that this arm is not displaceablein the direction of the axis of this rod but can, within certain limits.eifect rotations about this axis (of.

January 27. 193'! Figure 4). in. such a manner as to be displaceablealong and rotatable about its axis. By means of an am i fixed to therodh and carrying a square rod i lying between two adjusting screws 1 and Fin the arm I, the position oi. the rod It can be determined with respectto the arm I by slightly screwing back the one of the screws 1' and Iand readjusting the other of these screws until the pm i is in contactwith both screws. A spring 1', which acts'against the upper bearing ofthe rod h and against a collar it fast with this' rod, draws this roddownward. Against the lower side of the collar h lies the one end of afork k rotatable about a pin k the other end of this fork being providedwith a key k. Below this key It is a stop k resting on a support It onwhich the fork is is mounted. On the lower end of the rod h is fixed thedouble-armed armature l of an electromagnet l. The one end of thearmature l is fast with a spring 1 endeavouring to press the other endof this armature on a stop 1 against the action of the electromagnet.This electromagnet is operative only when the contact of a thermostat mis closed, on which the luminous crater of the electrode a is imagedwhen this electrode assumes a definite position.

The above-described mechanism operates as follows:

For the introduction of the electrode into the holder b, the key It isto be pressed down, so that the driving wheel 0 is slightly raisedagainst the action of the spring 7'. The hollow space in the The rod his mountedon the holder 11' wheel c thus assumes a central position withrespect to the axis B-B of the elctrode a, and the electrode can beinserted through this space. When the key k is then released (as isshown in the drawings), the driving wheel c assumes the positioneccentric to the electrode axis, and the points of the upper screws 0lie against the electrode. Energizing the motor 9 causes the drivingwheel 0 to rotate and the upper screws 0 to carry the electrode along.On account of the inclination oi! the axis AA to the electrode axis18-13 (of. Figure 3)., the screw points in engagement with the electrodepush this electrode'forward, which is due to the electrode effecting ascrew motion. The desired inclination of the axis A-A relative to theaxis BI B and, consequently, the

desired feed of the electrode per rotation can be adjusted by means ofthe screws and I. Unforeseen changes in the consumption of the electrodeare dealt with automatically by operation of the electromagnet I throughthe agency of the thermostat m.

, and thus imparting screw motions to said eIec- We claim: 1. In an arclamp, a holder for an electrode, a feeding mechanism for said electrode,said feeding mechanism having an annular wheel provided with a centralorifice through which the electrode passes and for feeding saidelectrode through said holder, said annular wheel being mounted 'on saidholder and rotatable about an axis crossing the axis of said electrodeat anacuteang'le and thus imparting screw motions to said'electrode whensaid annular wheel is rotated;

2. In an arc lamp, a holder for an electrode; a

, trode when said annular wheel is rotated.

3. In an arc lamp, a holder for an electrode, a feeding mechanism forsaid electrode, said feeding mechanism having an annular wheel providedwith a central orifice through which the electrode passes and feedingsaid electrode.

through said holder, the axis of said annular wheel being eccentric tothe axis of said electrode,

a bearing body for said annular wheel being mounted on said electrodeholder and rotatable about an axis intersecting the axis of rotationofsaid annular wheel at right angles, so that the rotation of saidbearing body alters the angle of inclination at which the axis ofrotation of said.

annular wheel.crosses the axis of said electrode, and means for rotatingsaid bearing body rela.-

tively to said electrode holder.

4. In an arc lamp, a holder for an electrode, a

feeding mechanism for said electrode, said feed: ing mechanism having anannular wheel provided with a central orifice through which theelectrode passes and feeding said-electrode through said holder, theaxis of said annular wheel being eccentric to the axis of saidelectrode, a bearing body for said annular wheel being mounted on saidelectrode holder and rotatable about an axis intersecting the axis ofrotation of said annular wheel at right angles, so that the rotation ofsaid bearing body alters the angle of inclination at which'the axis ofrotation of said' annular wheel crosses the axis of said electrode,'andan arc controlled means for rotating said bearing body relatively tosaidelectrode holder.

5. In an-arc lamp, .a holder for an electrode, a I

feeding mechanism forsaid electrode, said feeding mechanism having anannular wheel provided with a central orifice through which theelectrode passes and feeding said electrode through said holder, theaxis of said annular wheel being .ec-

centric to theaxis of said electrode, a bearing body for said annularwheel being mounted on said electrode holder and rotatable about anaxisinte'rsecting the axis of rotation-of said annular wheel at rightangles, so'that the rotation of -said bearing body alters the-angle ofinclination at which the axis-of rotation of said annular wheel crossesthe axis of said electrode, an electromagnet for, rotating said bearingbody relatively to" said electrode holder, and a thermostat positionedto receive light from the arc of the lamp and electrically connectedtosaid: electromagnet for controlling same.

- WALTER KURT- mime. ERNST SCl-IELLER.

